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MEDICINE MONOGRAPH CODE: [11.8]-C131 ID: TIP-MED-000401 ⚠️ HIGH-ALERT / SPECIALIST SUPERVISION

Divalproex Sodium

Active Ingredient / Scientific Identity: Divalproex Sodium • Class: Broad-Spectrum Antiepileptic & Mood Stabiliser (Enhances GABAergic Transmission via GABA Transaminase Inhibition & Blocks Voltage-Gated Sodium and T-Type Calcium Channels)

⚖️ Compare Profile
Generic / Entity NameDivalproex Sodium ([11.8]-C131)
Verified Indian Brands / RefGeneric Compendial Entry (No Commercial Brand Claimed)
Pharmacological ClassBroad-Spectrum Antiepileptic & Mood Stabiliser (Enhances GABAergic Transmission via GABA T
Available Dosage FormsControlled/Chrono-Release Tablets: 200 mg, 300 mg, 500 mg; Divalproex ER Tablets: 250 mg, 500 mg, 750 mg, 1000
Regulatory ClassificationSchedule H Prescription Drug • TERATOGENIC PREGNANCY PREVENTION PROGRAMME • NLEM 2022
Key Warning & Review DateSTRICTLY CONTRAINDICATED in acute or chronic hepatic disease or mitochondrial POLG disorders.
Reviewed: 2026-11-10
Safety Matrix:⚖️ Legal Status: Schedule H Prescription Drug • TERATOGENIC PREGNANCY🚨 Clinically High-Alert: Independent Dose & Route Verification Required

1. Clinical & Scientific Overview

Divalproex Sodium (TIP-MED-000401, Reference Code [11.8]-C131) is classified under Neurology & Antiepileptic Medicines (Ch 11) as a Broad-Spectrum Antiepileptic & Mood Stabiliser (Enhances GABAergic Transmission via GABA Transaminase Inhibition & Blocks Voltage-Gated Sodium and T-Type Calcium Channels). Within the Indian regulatory and compendial framework, it is governed under Schedule H Prescription Drug • TERATOGENIC PREGNANCY PREVENTION PROGRAMME • NLEM 2022.

Verified Indian Market Examples / Compendial Status:
Co-indexed constituent under primary monograph [11.8] (Sodium Valproate / Divalproex Sodium (Valproic Acid)). Representative Indian Market Examples (Edition 2.7 Ch 11 [11.8], p. 143): Sodium Valproate + Valproic Acid Controlled-Release (CR): Encorate Chrono (Sun Pharma—200, 300, 500 mg), Valparin Chrono / Alkalets (Sanofi), Epilex Chrono (Abbott). Divalproex Sodium Extended-Release: Dayo-OD / Dicorate-ER (Sun), Desval-ER, Trend-XR (250, 500, 750, 1000 mg) — Strengths & Forms: Controlled/Chrono-Release Tablets: 200 mg, 300 mg, 500 mg; Divalproex ER Tablets: 250 mg, 500 mg, 750 mg, 1000 mg; Oral Syrup: 200 mg/5 mL; IV Injection: 400 mg/4 mL
Co-indexed constituent under primary monograph [11.8] (Sodium Valproate / Divalproex Sodium (Valproic Acid)). Representative Indian Market Examples (Edition 2.7 Ch 11 [11.8], p. 143): Sodium Valproate + Valproic Acid Controlled-Release (CR): Encorate Chrono (Sun Pharma—200, 300, 500 mg), Valparin Chrono / Alkalets (Sanofi), Epilex Chrono (Abbott). Divalproex Sodium Extended-Release: Dayo-OD / Dicorate-ER (Sun), Desval-ER, Trend-XR (250, 500, 750, 1000 mg) — Strengths & Forms: Controlled/Chrono-Release Tablets: 200 mg, 300 mg, 500 mg; Divalproex ER Tablets: 250 mg, 500 mg, 750 mg, 1000 mg; Oral Syrup: 200 mg/5 mL; IV Injection: 400 mg/4 mL
Dosage Forms & Available Strengths:
Controlled/Chrono-Release Tablets: 200 mg, 300 mg, 500 mg; Divalproex ER Tablets: 250 mg, 500 mg, 750 mg, 1000 mg; Oral Syrup: 200 mg/5 mL; IV Injection: 400 mg/4 mL
Routes: Oral / Parenteral / Topical per formulation

3. Mechanism of Action & Pharmacodynamics

Pleiotropic central anticonvulsant mechanism: (1) prolongs recovery of voltage-gated Na+ channels (Nav) from fast inactivation; (2) blocks low-threshold T-type Ca2+ currents (Cav3) in thalamic relay neurons (explaining efficacy in 3-Hz spike-and-wave Absence seizures); (3) inhibits GABA transaminase (ABAT) and succinic semialdehyde dehydrogenase while stimulating glutamic acid decarboxylase (GAD), elevating brain GABA; and (4) inhibits Histone Deacetylase (HDAC).

4. Therapeutic Indications & Evidence-Supported Uses

  • Broad-spectrum epilepsy: Generalized tonic-clonic, absence, myoclonic (Juvenile Myoclonic Epilepsy), and focal seizures
  • Acute mania and maintenance prophylaxis in Bipolar I Disorder
  • Migraine prophylaxis (in non-pregnant patients without childbearing potential)

🇮🇳 Jurisdiction & Indication Note: Indications and schedules reflect Indian compendial and regulatory records (CDSCO / Indian Pharmacopoeia & NFI / NLEM 2022). Where international reference labels (US FDA DailyMed / NCBI StatPearls) are cited for pharmacokinetic or mechanistic parameters, international approvals do not automatically imply CDSCO approval in India.

5. Educational Dosage Context, Formulations & Administration

Educational Dosing & Regimen Summary: Adults: Start 10–15 mg/kg/day orally in 1–2 divided doses (Chrono CR); titrate by 5–10 mg/kg/week to 20–30 mg/kg/day (usual maintenance 600–2000 mg/day; target serum trough 50–100 mcg/mL).

Administration & Meal Timing: Oral (take with food to reduce GI irritation; swallow EC/CR tablets whole) or IV.

6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment

Absorption & Disposition:
Follows class pharmacokinetic profile detailed in parent monograph [11.8].
Metabolism & Biotransformation:
STRICTLY CONTRAINDICATED in acute or chronic hepatic disease or mitochondrial POLG disorders.
Elimination & Renal Adjustment:
No dose adjustment required, but monitor free valproate levels in uraemia/hypoalbuminaemia.
Hepatic Impairment Considerations:
STRICTLY CONTRAINDICATED in acute or chronic hepatic disease or mitochondrial POLG disorders.

7. Contraindications, Precautions & High-Risk Warnings

Contraindications & Red-Flag Precautions:
  • Pregnancy and women/girls of childbearing potential unless no alternative exists and a strict Pregnancy Prevention Programme is in place (highest teratogenicity among all AEDs: 10% congenital malformations [neural tube defects / spina bifida] + 30%–40% neurodevelopmental IQ decline!)
  • Hepatic disease, significant hepatic dysfunction, or urea cycle disorders
  • Known or suspected mitochondrial disorders caused by POLG mutations (Alpers-Huttenlocher syndrome) and children <2 years with suspected metabolic disease

Key Clinical Precautions: STRICTLY CONTRAINDICATED in acute or chronic hepatic disease or mitochondrial POLG disorders.

8. Adverse Effects Profile

Common & Mechanism-Related Adverse Effects:
  • Teratogenicity: Neural tube defects (spina bifida, anencephaly), craniofacial defects, and neurodevelopmental cognitive impairment
  • Idiosyncratic microvesicular hepatotoxicity (mediated by 4-ene-valproate, peak risk in children <2 yr on polytherapy) and acute haemorrhagic pancreatitis
  • Hyperammonaemic encephalopathy (can occur even with normal LFTs due to carnitine depletion; treated with L-Carnitine)
Serious / Dose-Limiting Adverse Effects:
  • Weight gain, PCOS/menstrual irregularities, tremor, reversible alopecia (zinc/selenium supplementation helps), and dose-related thrombocytopenia

9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions

  • Carbapenems (Meropenem, Imipenem, Ertapenem): inhibit intestinal absorption and acylpeptide hydrolase recycling of Valproate glucuronide, causing a catastrophic 60%–90% drop in serum Valproate levels within 24 hours and precipitating status epilepticus!
  • Lamotrigine: Valproate inhibits UGT1A4 glucuronidation of Lamotrigine, doubling its half-life to ~60 hr and precipitating fatal Stevens-Johnson Syndrome (SJS/TEN) unless Lamotrigine dose is halved!
  • Phenytoin & Phenobarbitone: Valproate displaces Phenytoin from albumin AND inhibits CYP2C9/Epoxide Hydrolase

10. Clinical Monitoring, Patient Counselling & Storage

Clinical & Laboratory Monitoring: Monitor clinical parameters per parent monograph [11.8].

Pharmacist Patient Counselling Points:

  • CRITICAL PREGNANCY WARNING: Valproate causes severe birth defects (spina bifida) and learning disabilities in unborn babies; women of childbearing potential must use effective contraception and consult their neurologist before planning pregnancy.
  • Seek immediate medical attention if persistent vomiting, severe abdominal pain (pancreatitis), confusion/drowsiness (high ammonia), or yellow eyes/dark urine develops.
  • Never switch or combine with Lamotrigine or hospital Carbapenem antibiotics without specialist dose verification.

Storage, Stability & Dispensing Safeguards: Store below 30°C in moisture-tight packaging (Sodium Valproate is highly deliquescent/hygroscopic).

11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)

THE 12-STEP ORAL DRUG JOURNEY THROUGH THE HUMAN BODY (LADME) Note: IV bolus enters Step 6 directly (F = 100%); Sublingual & Transdermal routes bypass Step 4–5 Portal First-Pass Metabolism 1. Oral Administration • Tablet / Capsule swallowed • Gastric emptying to duodenum pH 1.5–3.5 (Stomach) 2. Disintegration & Dissolution • Tablet breaks into granules • API dissolves in GI fluid Noyes-Whitney Dissolution Rate 3. GI Epithelial Absorption • Crosses intestinal villi • Passive / Active / P-gp efflux Small Intestine (Large Surface Area) 4. Portal Circulation • Mesenteric veins → Portal vein • Delivers blood to liver sinusoids Pre-systemic Venous Conduit 5. First-Pass Metabolism • Gut & hepatic CYP450 extraction • High: GTN, Propranolol, Morphine Determines Bioavailability (F = f_a × (1-E_H)) 6. Systemic Circulation • Hepatic vein → IVC → Heart • Unbound vs Albumin-bound drug Only FREE drug is active 7–8. Tissue Distribution (Vd) • Capillary permeation to organs • Blood-Brain & Placental barriers Vd = Dose / C_0 (L or L/kg) 9. Target Site of Action • Receptors (GPCR, Ion channel) • Enzymes & Carrier Transporters Pharmacodynamic Effect (E_max, EC50) 10. Hepatic Biotransformation • Phase I (CYP450 Oxidation/Hydrolysis) • Phase II (Glucuronidation/Sulfation) Converts lipophilic drug → hydrophilic metabolite 11. Renal & Biliary Elimination • Nephron: Filtration + Secretion − Reabsorption • Biliary excretion & Enterohepatic recycling Total Clearance CL_tot = CL_renal + CL_hepatic 12. Excretion from the Body • Urine (Primary polar metabolite route) • Bile/Faeces, Expired Air, Sweat, Milk Elimination Half-Life t1/2 = (0.693 × Vd) / CL
svg-v339-01-adme-12-step-journey — 8.1 Complete 12-Step Journey of an Orally Administered Drug (ADME): Figure 8.1: The 12-step physiological journey of a typical orally administered solid dosage form through Liberation, Absorption, Distribution, Metabolism, and Excretion (LADME). Note: Parenteral (IV), sublingual, and inhalational routes bypass gastrointestinal absorption and/or hepatic first-pass metabolism.

12. Authoritative References, Regulatory Sources & Editorial Disclaimer

Primary Compendial & Guideline Reference: Indian Pharmacopoeia (IP 2022) • NFI • CDSCO

Official Verification Portals: Indian Pharmacopoeia Commission (IPC) & National Formulary of India (NFI) • Central Drugs Standard Control Organization (CDSCO) • Ministry of Health & Family Welfare — NLEM 2022 • NCBI Bookshelf / StatPearls Pharmacology Reference • DailyMed (US FDA Official Prescribing Reference)

Last Medically & Pharmaceutically Reviewed: 2026-11-10 • Verification Status: VERIFIED_EDUCATIONAL_CONTENT

Educational & Clinical Disclaimer: This reference profile is published solely for pharmacy education, academic study, and professional clinical reference. It does not substitute for patient-specific clinical judgement, qualified specialist oncology/medical supervision, or official CDSCO/IP prescribing information. Never self-medicate with prescription, Schedule H/H1/X, NDPS, or oncology medicines.